Eportfolio and culture quandary

The eportfolio project marches on. Am using the Chalk & Wire product – a very powerful assessment engine. It is interesting how technology tools become the fulcrum of culture change. What I mean is: because eportfolio allows a fine-grained assessment of student work based on a rich mix of learning expression: reflection, expository writing, film, audio, visual art, etc. — the system is challenged to provide that level of assessment – basically forcing one up the levels of Bloom’s taxonomy and away from testing and an overwhelming emphasis on summative assessment (=the final: either you got the whole point of the course or you didn’t – and it’s too late to do anything about it!). At the same time, the tools shouldn’t drive the culture change.. then why does it end up so often doing just that ???